If you want to store 2.0 mJ of energy in a 10-μF capacitor,how much potential do you need to put across it?

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is given by the formula $E=\frac{1}{2}CV^2$, where $E$ is the energy in joules, $C$ is the capacitance in farads, and $V$ is the potential difference in volts.

We can rearrange this formula to solve for $V$:

$V=\sqrt{\frac{2E}{C}}=\sqrt{\frac{2(2.0	imes10^{-3}	ext{ J})}{10	imes10^{-6}	ext{ F}}}=\sqrt{400}=20	ext{ V}$

Therefore, the answer is choice D (20 V).

If You Want to Store 2